Oral care compositions for promoting gum health

ABSTRACT

Oral care compositions comprising an amino acid and stannous ion source, especially in the absence of zinc ion source, are provided for promoting Gum Health of a user.

FIELD OF THE INVENTION

The present invention relates to oral care compositions comprisingstannous ion source and an amino acid with absence of zinc ion sourcefor promoting Gum Health of a user. In particular, such oral carecompositions are useful for improving gingival wound healing andimproving the reduction of bacterial activity in the oral cavity of theuser.

BACKGROUND OF THE INVENTION

Gum disease, such as gingivitis and/or periodontitis, gives rise toacute and chronic gum inflammation in the oral cavity. “Gingivitis” isthe milder form of the disease. Symptoms of gingivitis may include:gingival bleeding; and redness, swollen, or tender gums. If leftuntreated, gingivitis can advance to “periodontitis”. Withperiodontitis, gums pull away from the teeth and form spaces called“periodontal pockets” that can become infected by pathogenic bacteria.The bacteria are present on the tooth root surfaces as biofilms. Thebacteria in the biofilms can attack the gingival and underlying alveolarbone supporting teeth. These attacks can cause major damage to the softtissue and bone that support teeth. In the later stage of gum disease(i.e., “advanced periodontitis”), more serious problems of loosening ofteeth and eventual tooth loss can occur.

Some commercially available oral care compositions aim, principally, atalleviating one or more symptoms of the earlier stage of gum disease(i.e., gingivitis), which includes: relief of red, swollen, or tendergums; and/or stem gum bleeding. Typically, these compositions claimbenefits such as, “gum care”, “oral care”, “oral health”, “dental care,”or “dental health” to users. An example of such a composition is“Colgate® Total” toothpaste, which they claim to “help reduce the firststage of gum disease”, which is defined as “gingivitis, or bleedinggums” (seehttp://www.colgatetotal.com/total-benefits/whole-mouth-health/gingivitis-control).To help distinguish the benefits of the commercially available oral carecompositions versus the present invention, the inventors herein refer tothe aforementioned benefits of these commercially available oral carecompositions collectively as “Gum Care”. This is because thesecommercially available oral care compositions have been formulatedprimarily to care for the gums and relieve the symptoms (e.g., gumbleeding; and/or redness, swelling, or tender gums) associated with theearlier stage of gum disease (i.e., gingivitis).

However, there is a need to provide overall “Gum Health” benefits, whichas used herein, is a broader term and is intended to encompass at leastsome of the aforementioned Gum Care benefits, as well as providingadditional anti-bacterial benefits to mitigate the harmful effects ofbacteria as it relates to gum disease, including gingivitis,periodontitis, or both.

There is at least one of several drawbacks to the above describedconventional approaches. Firstly, these commercially available oral carecompositions may promote Gum Care, but they do not go far enough to alsopromote Gum Health. In fact, these commercially available oral carecompositions generally fail to provide any significant anti-bacterialeffects in addition to the Gum Care benefits (e.g., anti-bleeding and/oranti-swelling). This is a problem because if the bacteria in thebiofilms are not controlled, they can then increase the size of theperiodontal pockets leading to periodontitis. Secondly, Gum Health maycorrelate to overall body health. In other words, an individual's GumHealth can be an indicator of the person's overall body health. Studiessuggest that the risk of developing any one (or more) of these potentiallife-threatening conditions such as, for example, heart disease andstroke, diabetes, kidney disease, preterm birth, and/or osteoporosis,may increase as overall Gum Health decreases (see U.S. Pat. No.6,846,478; Doyle, M. J.; & U.S. Pat. No. 8,283,135; Doyle, M. J.). Thus,it is desirable to improve overall Gum Health, not just Gum Care, inorder to ensure better overall body health.

Stannous salts, such as stannous fluoride has been used in oral carecompositions as to provide Gum Health benefit, including antimicrobialeffect, reduced gingivitis, decreasing progression to periodontaldisease, reductions in dentinal hypersensitivity, and reduced coronaland root dental caries and erosion. However, there are disadvantages forconventional stannous containing compositions. A first side effectroutinely encountered during use of effective stannous fluorideformulations is unacceptable formulation astringency. secondly,formulating stannous ions stably also presents a challenge as the tin(II) ion is both prone to oxidation towards tin (IV) and to precipitatefrom aqueous solution as stannous hydroxide. Thirdly, stannous saltstend to discolor the oral care compositions, turning them yellow to darkbrown. In order to overcome this problem, those conventional stannouscontaining compositions further comprising additional components suchas, for example, TiO₂, folic acid or flavor mixtures (e.g., methylsalicylate, menthol, eugenol and cineol) to prevent the above-describeddiscoloration in storage without significantly diminishing the stabilityand activity of stannous salts. Therefore, it is desired to simplifyformulations and processing steps to provide cost effective andefficacious toothpaste and other oral care formulations.

Oral care compositions containing stannous salts and zinc ion sourcehave been described. Soluble zinc salts, such as zinc citrate, have beenused in dentifrice compositions, but have several disadvantages. Freezinc ions may react with fluoride ions to produce zinc fluoride, whichis insoluble and so reduces the availability of both the zinc and thefluoride. Moreover, zinc ions in solution impart an unpleasant,astringent mouthfeel, so formulations that provide effective levels ofzinc, and also have acceptable organoleptic properties, have beendifficult to achieve. Finally, the zinc ions will react with anionicsurfactants such as sodium lauryl sulfate, thus interfering with foamingand cleaning. Therefore, there is a need to optimize the usage of zincin the formulation.

Therefore, there is a continuous need to provide an oral carecomposition that provides Gum Health benefits to users, or at leastprovide better associated Gum Health benefits (e.g., gingival woundhealing and anti-bacterial benefits) than those compositions that arecommercially available.

SUMMARY OF THE INVENTION

The present invention attempts to address this need based, at least inpart, on the surprising discovery that the combination of an amino acidand a stannous ion source in absence of zinc ion source in an oral carecomposition promotes Gum Health benefits that include at least gingivalwound healing and anti-bacterial benefits. In particular, the oral carecomposition comprises amino acid for gingival wound healing, andstannous ion source as an anti-bacterial agent without the presence ofzinc ion source to combat the undesirable effects of bacteria activityin the oral cavity.

One advantage of the present invention is “better deep biofilmpenetration and/or bacteria kill”. To this end, it is furthersurprisingly found that the penetration depth and/or penetration rate ofstannous ion into the biofilms may be increased, when used incombination with amino acid, especially in absence of zinc ion. Inshort, the synergistic combination of amino acid and stannous ion sourcewithout presence of zinc ion source in the oral care composition may besuch that an improvement in the Gum Health benefit is achieved.Furthermore, the use of the oral care compositions of the presentinvention may provide the users an improved Gum Health benefit.

Another advantage of the present invention is to provide oral carecompositions for promoting Gum Health as it relates to the totality ofsymptoms associated with gingivitis, periodontitis, or both. It is yet afurther advantage that the oral care compositions of the presentinvention have improved Gum Health benefits. It is yet a furtheradvantage of the present invention to provide oral care compositionshaving improved penetration depth of the anti-bacterial agent(s) intothe biofilms. It is yet a further advantage of the present invention toprovide oral care compositions having improved penetration rate of theanti-bacterial agent(s) into the biofilms. It is yet a further advantageof the present invention to provide cost effective and efficacious oralcare compositions for promoting Gum Health. It is yet a furtheradvantage that the oral care composition, is a dentifrice, andpreferably provides pleasant taste and mouth-feel experience. It is yeta further advantage that the oral care compositions have physical andchemical stability across a range of manufacturing, handling and storageconditions. It is yet a further advantage that the oral carecompositions have a stable quality of end product (e.g., consistentvisual appearance and no discoloration, gingival wound healingperformance, etc.) even after three months storage at 40° C. It is yet astill further advantage that the oral care compositions of the presentinvention minimize the use of anti-bacterial agents. It is yet a stillfurther advantage that the oral compositions of the present inventionminimize the amount of the amino acid to reduce and/or eliminate theinstability and/or discoloration problems as described above.

In one aspect, the present invention is directed to an oral carecomposition, comprising: (a) from 0.01% to 5%, by weight of thecomposition, of a stannous ion source; and (b) from 0.01% to 10%, byweight of the composition, of an amino acid in free or salt form;wherein the oral care composition is substantially free of zinc ionsource. Preferably, the oral care composition is essentially free ofzinc ion source. More preferably, the oral care composition is free ofzinc ion source.

Preferably, the amino acid used in the present invention is selectedfrom the group consisting of arginine, lysine, citrulline, ornithine,creatine, histidine, diaminobutanoic acid, diaminoproprionic acid,aspartic acid, glutamic acid, glycine, asparagine, glutamine andcombinations thereof; preferably the amino acid is present in the amountof 0.1% to 5%, more preferably from 0.3% to 3%, by weight of thecomposition. The amino acid can be in their free form or salts form.

In yet still another aspect of the present invention, a method isprovided for promoting Gum Health in a human subject comprisingadministering to the subject's oral cavity an oral care composition ofthe present invention.

These and other features of the present invention will become apparentto one skilled in the art upon review of the following detaileddescription when taken in conjunction with the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims that particularly pointout and distinctly claim the invention, it is believed the presentinvention will be better understood from the following description ofthe accompanying figures.

FIG. 1 is a perspective view of an oral splint with Hydroxyapatite(“HA’) disks attached thereto.

FIG. 2 is a perspective view of the HA disk having grooves therein.

FIG. 3 is a schematic of a cross sectional view of the groove withbiofilm therein.

DETAILED DESCRIPTION OF THE INVENTION Definitions

As used herein, the articles including “a” and “an” when used in aclaim, are understood to mean one or more of what is claimed ordescribed.

The terms “alleviate” and “alleviating” are used interchangeably andmeans minimizing, preventing, delaying, and/or treating at least onesymptom of gum disease to effect positive change (i.e., benefit) to theuser.

The term “biofilms” as used herein means a matrix-enclosed bacterialpopulation adherent to each other and/or to surfaces or interfaces inthe oral cavity.

The term “comprising” as used herein means that steps and ingredientsother than those specifically mentioned can be added. This termencompasses the terms “consisting of” and “consisting essentially of.”The compositions of the present invention can comprise, consist of, andconsist essentially of the essential elements and limitations of theinvention described herein, as well as any of the additional or optionalingredients, components, steps, or limitations described herein.

The term “dentifrice” as used herein means paste, gel, powder, tablets,or liquid formulations, unless otherwise specified, that are used toclean the surfaces of the oral cavity.

The term “Gum Care” as used herein refers to inherent or promotedbenefits of an oral care composition directed, principally, toalleviating one or more symptoms associated with an early stage of gumdisease (i.e., gingivitis). Such symptoms may include, for examplebleeding gums; and red, swollen, or tender gums.

The term “Gum Health” as used herein refers to inherent or promotedbenefits of an oral care composition to provide “Gum Care” benefits thatinclude at least improve gingival wound healing, as well as, providingadditional improve reduction of bacterial activity to mitigate theharmful effects of bacteria as it relates to gum disease, includinggingivitis, periodontitis or both.

The term “improve reduction of bacterial activity” as used herein meansreduce bacterial activity in the oral cavity as determined by the assaydescribed in Example B.

The term “improve gingival wound healing” as used herein means reducegum bleeding in the oral cavity as determined by the wound healing assaydescribed in Example C.

The term “oral care composition” or “oral care compositions” as usedherein means a product that in the ordinary course of usage is retainedin the oral cavity for a time sufficient to contact some or all of thedental surfaces and/or oral tissues for purposes of oral activity. Inone example, the composition provides a gum care benefit when used inthe oral cavity. The oral care composition of the present invention maybe in various forms including toothpaste, dentifrice, tooth gel, toothpowders, tablets, rinse, mouthwash, sub gingival gel, foam, mouse,chewing gum, lipstick, sponge, floss, prophy paste, petrolatum gel,denture adhesive, or denture product. In one example, the oralcomposition is in the form of a paste or gel. In another example, theoral composition is in the form of a dentifrice. The oral compositionmay also be incorporated onto strips or films for direct application orattachment to oral surfaces, or incorporated into floss.

The term “amino acid” used herein the present invention refers to theamino acid including both in free form and salts form.

The term “partially water soluble” as used herein means a compound has asolubility of 1 g/1000 ml or more at 25° C.

The term “effective amount” as used herein means an amount of a compoundor composition sufficient to induce a positive benefit, an oral healthbenefit, and/or an amount low enough to avoid serious side effects,i.e., to provide a reasonable benefit to risk ratio, within the soundjudgment of a skilled artisan. In one example, “effective amount” meansat least 0.01% of the material, by weight of the composition,alternatively at least 0.1%.

As used herein, the words “preferred”, “preferably” and variants referto embodiments of the invention that afford certain benefits, undercertain circumstances. However, other embodiments may also be preferred,under the same or other circumstances. Furthermore, the recitation ofone or more preferred embodiments does not imply that other embodimentsare not useful, and is not intended to exclude other embodiments fromthe scope of the invention.

The term “promoting” as used herein means to promote and/or enhance theGum Health benefits associated with using the oral care compositions ofthe present invention in the oral cavity.

The term “substantially free” as used herein refers to no intentionalamount of that material is added to the composition or an amount of amaterial that is less than 0.05%, 0.01%, or 0.001% of the composition.The term “essentially free” as used herein means that the indicatedmaterial is not deliberately added to the composition, or preferably notpresent at analytically detectable levels. It is meant to includecompositions whereby the indicated material is present only as animpurity of one of the other materials deliberately added. The term“free” as used herein refers to no reasonably detectable amount of thatmaterial is present in the composition.

The term “synergistic Gum Health benefit” as used herein meansanalytically measurable increases in any two Gum Health benefits thatinclude at least improve gingival wound healing and improve reduction ofbacterial activity in the oral cavity, that is more than additive.

The term “teeth” as used herein refers to natural teeth as well asartificial teeth or dental prosthesis.

The term “total water content” as used herein means both free water andwater that is bound by other ingredients in the oral care composition.

All percentages, parts and ratios are based upon the total weight of thecompositions of the present invention, unless otherwise specified. Allsuch weights as they pertain to listed ingredients are based on theactive level and, therefore do not include solvents or by-products thatmay be included in commercially available materials, unless otherwisespecified.

All measurements referred to herein are made at 25° C. (i.e., roomtemperature) unless otherwise specified.

Oral Care Compositions

It has been surprisingly discovered that the combination of stannous ion(i.e., an anti-bacterial agent) and an amino acid, in the absence ofzinc ion source, in an oral care composition is particularly useful forpromoting Gum Health benefits to users. In particular, the surprisingdiscovery was that the penetration of the stannous ion into the biofilmsis markedly improved when combined with the amino acid. Without wishingto be bound by theory, the amino acid contains both carboxylic and aminegroups. It is believed that the stannous ions can bind strongly to thesechemical moieties on amino acid to positively influence the penetrationof stannous ions into the biofilms.

It has also been surprisingly found that the penetration depth and/orthe penetration rate of stannous ions into the biofilms may beincreased, or markedly increased, when formulated with amino acid,especially without the presence of zinc. In short, the absence of zincion source and the presence of amino acid in combination with stannousion source in an oral care composition aids the composition's efficacyin mediating the harmful effects of the bacteria in the biofilms on thegums.

In one aspect, the present invention is directed to an oral carecomposition comprising: a) from 0.01% to 5%, preferably from 0.05% to4%, more preferably from 0.1% to 2%, by weight of the composition, of astannous ion source; b) from 0.01% to 10%, preferably from 0.05% to 5%,more preferably from 0.1% to 2%, by weight of the composition, of anamino acid; and c) from 0% to 0.01%, by weight of the composition, ofzinc ion source.

Stannous Ion Source

The present invention relates to the above mentioned oral carecompositions comprising, in a preferred example, the stannous ion sourcepresent in the amount of from 0.01% to 5%, preferably from 0.05% to 4%,or more preferably from 0.1% to 2%, by weight of the composition, toprovide anti-bacterial effectiveness. The stannous ion source usedherein may include any safe and effective stannous salt. Suitableexamples of stannous ion source are selected from the group consistingof stannous chloride, stannous fluoride, stannous acetate, stannousgluconate, stannous oxalate, stannous sulfate, stannous lactate,stannous tartrate, stannous iodide, stannous chlorofluoride, stannoushexafluorozirconate, stannous citrate, stannous malate, stannousglycinate, stannous carbonate, stannous phosphate, stannouspyrophosphate, stannous metaphosphate, and combinations thereof.Preferably, the stannous ion source is selected from stannous fluoride,stannous chloride, and combinations thereof. In one preferred example,the stannous ion source comprises stannous chloride. In anotherpreferred example, the stannous ion source comprises stannous fluoride.

Amino Acids

The term “amino acids” as used herein include not only naturallyoccurring amino acids, but also any amino acids having an amino groupand a carboxyl group in the molecule, which are water-soluble andpharmaceutically acceptable considered to be physiologically acceptablein the amounts and concentrations provided.

Suitable amino acids used in the present invention include, but notlimited to, a basic amino acid such as arginine, lysine, serine,histidine, ornithine; a neutral amino acid such as alanine,aminobutyrate, asparagine, citrulline, cysteine, cystine, glutamine,glycine, hydroxyproline, isoleucine, leucine, methionine, phenylalanine,proline, serine, taurine, threonine, tryptophan, tyrosine, valine; or anacidic amino acid such as aspartic acid, glutamic acid; or combinationsthereof. Each of said amino acids can be in its free form or in its saltform or a combination thereof. If the amino acid is in its salt form,suitable salts include salts known in the art to be pharmaceuticallyacceptable salts considered to be physiologically acceptable in theamounts and concentrations provided.

Preferably, the amino acids used in the present invention are selectedfrom the group consisting of arginine, lysine, citrulline, asparagine,glutamine, glycine, aspartic acid, glutamic acid, and combinationsthereof.

In some examples, the amino acid is selected from arginine, lysine,citrulline, in free form or salt form, or combinations thereof. In someexamples, the amino acid is selected from asparagine, glutamine, orglycine, in free form or salt form, or combinations thereof. In someother examples, the amino acid is selected from aspartic acid, glutamicacid, in free form or salt form, or combinations thereof. If the aminoacid is aspartic acid or glutamic acid in its salt form, non-limitingexamples of such salts include those derived from alkali metals such aspotassium and sodium or alkaline earth metals such as calcium andmagnesium.

Preferably the amino acid is present in the amount of from 0.01% to 10%,from 0.05% to 5%, yet more preferably from 0.1% to 2%, alternativelyfrom 0.2% to 3%, by weight of the composition.

Free of Zinc Ion Source

Preferably, the oral care compositions comprise from 0% to 0.01%, byweight of the composition, of a zinc ion source. Preferably, the zincion source is selected from zinc citrate, zinc chloride, zinc sulfate,zinc gluconate, zinc lactate, zinc phosphate, zinc oxide, zinccarbonate, and combinations thereof. More preferably, the zinc ionsource is present in the amount of from 0% to less than 0.005%, orpreferably from 0% to 0.001%, by weight of the composition; morepreferably the oral care composition is free of zinc ion source.

Thickening Agent

The oral care compositions of the present invention may comprise athickening agent. Preferably the oral care composition comprises from0.1% to 5%, preferably from 0.8% to 3.5%, more preferably from 1% to 3%,yet still more preferably from 1.3% to 2.6%, by weight of thecomposition, of the thickening agent.

Preferably the thickening agent comprises a thickening polymer, athickening silica, or a combination thereof. Yet more preferably, whenthe thickening agent comprises a thickening polymer, the thickeningpolymer is selected from a charged carboxymethyl cellulose, a non-ioniccellulose derivative, a linear sulfated polysaccharide, a natural gum,polymers comprising at least a polycarboxylated ethylene backbone, andcombinations thereof.

In one example the thickening silica is obtained from sodium silicatesolution by destabilizing with acid as to yield very fine particles. Onecommercially available example is ZEODENT® branded silicas from HuberEngineered Materials (e.g., ZEODENT® 103, 124, 113 115, 163, 165, 167).

Preferably the linear sulfated polysaccharide is a carrageenan (alsoknown as carrageenin). Examples of carrageenan includeKappa-carrageenan, Iota-carrageenan, Lambda-carrageenan, andcombinations thereof.

In one example the CMC is prepared from cellulose by treatment withalkali and monochloro-acetic acid or its sodium salt. Differentvarieties are commercially characterized by viscosity. One commerciallyavailable example is Aqualon™ branded CMC from Ashland SpecialIngredients (e.g., Aqualon™ 7H3SF; Aqualon™ 9M3SF Aqualon™ TM9A;Aqualon™ TM12A).

Preferably a natural gum is selected from the group consisting of gumkaraya, gum arabic (also known as acacia gum), gum tragacanth, xanthangum, and combination thereof. More preferably the natural gum is xanthangum. Xanthan gum is a polysaccharide secreted by the bacteriumXanthomonas campestris. Generally, xanthan gum is composed of apentasaccharide repeat units, comprising glucose, mannose, andglucuronic acid in a molar ratio of 2:2:1, respectively. The chemicalformula (of the monomer) is C₃₅H₄₉O₂₉. In one example, the xanthan gumis from CP Kelco Inc (Okmulgee, US).

Preferably, the non-ionic cellulose or derivative thereof has an averagemolecular weight range of 50,000 to 1,300,000 Daltons, and preferably anaverage degree of polymerization from 300 to 4,800. More preferably, thenon-ionic cellulose or derivative thereof is hydroxyethyl cellulose(“HEC”).

Preferably the polymer comprising at least a polycarboxylated ethylenebackbone is selected from the group consisting of: co-polymers of maleicanhydride with methyl vinyl ether having a molecular weight of 30,000 to1,000,000 Daltons; homo-polymers of acrylic acid; and co-polymers ofmaleic acid and acrylic acid or methacrylic.

The co-polymers of maleic anhydride with methyl vinyl ether are at leastone of: Gantrez AN139 (M.W. 500,000 daltons), Gantrez AN119 (M.W.250,000 daltons), or S-97 Pharmaceutical Grade (M.W. 70,000 daltons);and the homo-polymers of acrylic acid and co-polymers of maleic acid andacrylic acid or methacrylic acid are at least one of: Acusol 445, Acusol445N, Accusol 531, Acusol 463, Acusol 448, Acusol 460, Acusol 465,Acusol 490, Sokalan CPS, Sokalan CP7, Sokalan CP45, or Sokalan CP12S;and (v) combinations thereof.

In an example, the GANTREZ™ series of polymers are co-polymers of maleicanhydride with methyl vinyl ether having a molecular weight (M.W.) of30,000 daltons to 1,000,000 daltons. These co-polymers are available forexample as GANTREZ™ AN139 (M.W. 500,000 daltons), AN119 (M.W. 250,000daltons) and S-97 Pharmaceutical Grade (M.W. 70,000 daltons), fromAshland Chemicals (Kentucky, USA).

In another example, the ACUSOL™ and the SOKALAN series of polymersinclude homopolymers of acrylic acid and copolymers of maleic acid andacrylic acid or methacrylic. Examples are 0:1000 to 1000:0 copolymers ofmaleic acid with acrylic acid having a molecular weight (M.W.) of about2,000 to about 1,000,000. These copolymers are commercially available asACUSOL™ 445 and 445N, ACUSOL™ 531, ACUSOL™ 463, ACUSOL™ 448, ACUSOL™460, ACUSOL™ 465, ACUSOL™ 497, ACUSOL™ 490 from Dow Chemicals (Michigan,USA) and as Sokalan® CP 5, Sokalan® CP 7, Sokalan® CP 45, and Sokalan®CP 12 S from BASF (New Jersey, USA).

In another example, the crosslinked polyacrylic acid (PAA) polymer is ageneric term for the synthetic high molecular weight polymers of acrylicacid. These may be homopolymers of acrylic acid, crosslinked with anallyl ether pentaerythritol, allyl ether of sucrose or allyl ether ofpropylene. And, in a water solution at neutral pH, PAA is an anionicpolymer, i.e. many of the side chains of PAA will lose their protons andacquire a negative charge. Carbopol®-type polymers, such as Carbopol®,Pemulen® and Noveon®, are polymers of acrylic acid, crosslinked withpolyalkenyl ethers or divinyl glycol. Carbomer commercial codes, e.g.940™, indicate the molecular weight and the specific components of thepolymer.

Anti-Caries Agent

Optionally, but preferably, the oral care compositions may include aneffective amount of an anti-caries agent. In one aspect, the anti-cariesagent is a fluoride ion source. Suitable examples of fluoride ions maybe selected from a source comprising stannous fluoride, sodium fluoride,potassium fluoride, sodium monofluorophosphate (“MFP”), indium fluoride,amine fluoride, zinc fluoride, and mixtures thereof. Preferably, thefluoride ion source is selected from sodium fluoride, stannous fluoride,MFP, or combinations thereof. The fluoride ion source may be present inan amount of from 0.0025% to 10%, or from 0.05% to 4%, or from 0.1% to2%, or preferably from 0.2% to 1.5%, by weight of the composition, toprovide anti-caries effectiveness. In certain examples, the fluoride ionsource can be present in an amount sufficient to provide fluoride ionsconcentration in the composition at levels from 25 ppm to 25,000 ppm,generally at least from 500 ppm to 1600 ppm, for example 1100 ppm or1450 ppm. The appropriate level of fluoride will depend on theparticular application. A toothpaste for general user would typicallyhave about 1000 to 1500 ppm, with pediatric toothpaste having somewhatless.

pH

The pH of the oral care composition of the present invention may be from4 to 11, preferably from pH 5 to 9, or more preferably from pH 5.0 to7.2. Preferably, the pH is less than 7.2, more preferably the pH is 7.0or less, even more preferably the pH is from pH 5.3 to pH 7.0,alternatively the pH is from pH 6.0 to less than pH 7.0, e.g., pH 6.9,or pH 6.8, or pH 6.7, or pH 6.6, or pH 6.5, or pH 6.4, or pH 6.3, or pH6.2, or pH 6.2, or pH 6.1, or pH 6.0. The relatively low pH of thepresent inventive composition is for alleviating discoloration andoptionally avoiding the precipitation of stannous. Without wishing to bebound theory, at above pH 7.3 stannous ion may increase the possibilityof discoloration. Thus, it is desirable to have the oral carecomposition have a less than pH 7.0 to alleviate discoloration.

The pH is typically measured using a ratio of 1:3 of paste:water,whereby 1 gram of the oral care composition (e.g., toothpaste) is mixedinto 3 grams of deionized water, and then the pH is assessed with anindustry accepted pH probe that is calibrated under ambient conditions.The pH is measured by a pH meter with Automatic Temperature Compensating(ATC) probe. For purposes of clarification, although the analyticalmethod describes testing the oral care composition when freshlyprepared, for purposes of claiming the present invention, the pH may betaken at any time during the product's reasonable lifecycle (includingbut not limited to the time the product is purchased from a store andbrought to the user's home).

After each usage the electrode should be washed free from the samplesolution with water. Remove any excess water by wiping with a tissue,such as Kimwipes or equivalent. When electrode is not in use, keepelectrode tip immersed in pH 7 buffer solution or electrode storagesolution. Equipment details are as follows:

-   -   pH Meter: Meter capable of reading to 0.01 or 0.001 pH units.    -   Electrode: Orion Ross Sure-Flow combination: Glass body—VWR        #34104-834/Orion #8172BN or VWR #10010-772/Orion #8172BNWP.        -   Epoxy body—VWR #34104-830/Orion #8165BN or VWR            #10010-770/Orion #8165BNWP.        -   Semi-micro, epoxy body—VWR #34104-837/Orion #8175BN or VWR            #10010-774/Orion #3175BNWP.        -   Orion PerpHect combination: VWR #34104-843/Orion #8203BN            semi-micro, glass body.    -   ATC Probe: Fisher Scientific, Cat. #13-620-16.        pH Modifying Agent

The oral care compositions herein may optionally include an effectiveamount of a pH modifying agent, alternatively wherein the pH modifyingagent is a pH buffering agent. The pH modifying agents, as used herein,refer to agents that can be used to adjust the pH of the oral carecompositions to the above-identified pH range. The pH modifying agentsinclude hydrochloric acid, alkali metal hydroxides, ammonium hydroxide,organic ammonium compounds, carbonates, sesquicarbonates, borates,silicates, phosphates, imidazole, and mixtures thereof.

Specific pH modifying agents include monosodium phosphate (monobasicsodium phosphate), trisodium phosphate (sodium phosphate tribasicdodecahydrate or TSP), sodium benzoate, benzoic acid, sodium hydroxide,potassium hydroxide, alkali metal carbonate salts, sodium carbonate,imidazole, pyrophosphate salts, polyphosphate salts both linear andcyclic form, sodium gluconate, lactic acid, sodium lactate, citric acid,sodium citrate, phosphoric acid.

In one example, 0.01% to 3%, preferably from 0.1% to 1% of TSP by weightof the composition, and 0.001% to 2%, preferably from 0.01% to 0.3% ofmonosodium phosphate by weight of the composition is used. Withoutwishing to be bound by theory, TSP and monosodium phosphate may havecalcium ion chelating activity and therefore provide somemonofluorophosphate stabilization (in those formulations containingmonofluorophosphate).

Water

Water is commonly used as a carrier material in oral care compositionsdue to its many benefits. For example, water is useful as a processingaid, is benign to the oral cavity and assists in quick foaming oftoothpastes. Water may be added as an ingredient in its own right or itmay be present as a carrier in other common raw materials such as, forexample, sorbitol and sodium lauryl sulfate.

In some examples, the oral care compositions herein may include from 10%to 70%, or preferably from 15% to 30%, by weight of the composition, oftotal water content. The term “total water content” as used herein meansthe total amount of water present in the oral care composition, whetheradded separately or as a solvent or carrier for other raw materials butexcluding that which may be present as water of crystallization incertain inorganic salts. Preferably, the water is USP water.

Alternatively, in other examples, the oral care compositions herein mayinclude from 0% to 5%, by weight of the composition, of total watercontent. For example, the oral care composition may be substantiallyfree of water, preferably free of water.

Surfactant

Optionally, but preferably, the oral care compositions comprise asurfactant. The surfactant may be selected from anionic, nonionic,amphoteric, zwitterionic, cationic surfactants, or combinations thereof,preferably the surfactant is anionic, more preferably the anionicsurfactant is sodium lauryl sulfate (SLS). An example of a zwitterionicsurfactant is cocamidopropyl betaine. The oral care composition maycontain one, two, or more surfactants. The composition may include asurfactant at a level of from 0.1% to 20%, preferably from 1% to 10%, byweight of the total composition.

Humectants

The oral care compositions herein may include humectants present in theamount of from 0% to 70%, or from 15% to 55%, by weight of thecompositions. Humectants keep oral care compositions from hardening uponexposure to air and certain humectants may also impart desirablesweetness of flavor to oral care compositions. Suitable examples ofhumectants may include glycerin, sorbitol, polyethylene glycol,propylene glycol, xylitol, trimethyl glycine, and mixtures thereof.Other examples may include other edible polyhydric alcohols. In someexamples, the humectant is selected from sorbitol, glycerin, andcombinations thereof. Preferably the humectant is sorbitol. In anexample, the composition comprises from 10% to 66%, alternatively from30% to 55%, of humectant by weight of the composition.

Abrasives

The oral care compositions of the present invention comprise aneffective amount of an abrasive. Examples of abrasives include acalcium-containing abrasive, a silica, or combinations thereof. Ifcontaining a calcium-containing abrasive, the calcium-containingabrasive is preferably selected from the group consisting of calciumcarbonate, dicalcium phosphate, tricalcium phosphate, calciumorthophosphate, calcium metaphosphate, calcium polyphosphate, calciumoxyapatite, sodium carbonate, sodium bicarbonate, and combinationsthereof. If a silica, preferably the silica is a precipitated silica(e.g., sodium silicate solution by destabilizing with acid as to yieldvery fine particles) such as those from the ZEODENT® series from HuberEngineered Materials (e.g., ZEODENT® 103, 124, 113 115, 163, 165, 167).It is acknowledged that some of these silicas (e.g., synthetic amorphoussilica) can perform both abrasive and thickening functions, but areincluded herein under the term “abrasive” for purposes of the presentinvention. Preferably the oral care composition comprises from 1% to35%, more preferably from 5% to 25% of abrasive, by weight of thecomposition.

Flavoring Agent

The oral care composition herein may include from 0.01% to 5%,preferably from 0.1% to 2%, by weight of the composition, of a flavoringagent. Examples of suitable flavoring agent that may be used in the oralcare composition include those described in U.S. Pat. No. 8,691,190;Haught, J. C., from column 7, line 61 to column 8, line 21. In someexamples, the flavoring agent may be selected from methyl salicylcate,menthol, eugenol and cineol. In some examples, the oral care compositionmay comprise a flavor mixture which is free of or substantially free ofmethyl salicylcate, menthol, eugenol and cineol.

Sweetener

The oral care compositions herein may include a sweetening agent. Thesweetening agent is generally present in the oral care compositions atlevels of from 0.005% to 5%, by weight of the composition. Suitableexamples of sweetener include saccharin, dextrose, sucrose, lactose,xylitol, maltose, levulose, aspartame, sodium cyclamate, D-tryptophan,dihydrochalcones, acesulfame, sucralose, neotame, and mixtures thereof.Other suitable examples of sweetener are described in U.S. Pat. No.8,691,190; Haught, J. C. from column 9, line 18 to column 10, line 18.

Coloring Agents

The oral care compositions herein may include a coloring agent presentin the amount of from 0.001% to 0.01%, by weight of the compositions.The coloring agent may be in the form of an aqueous solution, preferably1% coloring agent in a solution of water. Suitable examples of coloringagents may include pigments, pealing agents, filler powders, talc, mica,magnesium carbonate, calcium carbonate, bismuth oxychloride, zinc oxide,and other materials capable of creating a visual change to the oral carecompositions. Other suitable examples may include titanium dioxide(TiO₂). Titanium dioxide is a white powder which adds opacity to thecompositions and is generally present in the oral care compositions atlevels of from 0.25% to 5%, by weight of the composition.

Other Ingredients

The present oral care composition can comprise the usual andconventional ancillary components that are known to one skilled in theart. Optional ingredients include, for example, but are not limited to,anti-plaque agent, anti-sensitivity agent, whitening and oxidizingagent, anti-inflammatory agent, anti-calculus agent, chelating agent,tooth substantive agent, analgesic and anesthetic agent. It will beappreciated that selected components for the oral care compositions mustbe chemically and physically compatible with one another.

Method of Use

In one aspect, the present invention relates to a method for cleaning orpolishing teeth in a human subject. The method of cleaning or polishingherein comprises contacting a subject's teeth with the oral carecompositions according to the present invention.

In another aspect, the present invention also relates to a method ofpromoting Gum Health in a human subject comprising administering to thesubject's oral cavity an oral care composition according to the presentinvention, wherein preferably the administering occurs at least once aday, more preferably at least twice a day.

In yet another aspect, the present invention relates to a use of aminoacid for making an oral care composition containing stannous, especiallycontaining no zinc, for promoting Gum Health in a human subject.Preferably, the method of promoting Gum Health occurs at least within aperiod selected from the group consisting of:

a) from time 0 hours to 72 hours;

b) from time 0 hours to 48 hours;

c) from time 0 hours to 24 hours;

-   -   wherein time 0 hour is the time when the oral care composition        according to the present invention is administrated.

In yet another aspect, the present invention also relates to a method ofpromoting Gum Health, wherein promoting Gum Health comprises:

(i) improving gingival wound healing in the oral cavity; and

(ii) improve reduction of bacterial activity in the oral cavity.

The methods as described above may be by brushing (e.g., toothbrushing)with an oral care composition (e.g., dentifrice) or rinsing with an oralcare composition (e.g., dentifrice slurry or mouth rinse). The oral carecompositions may be applied neat or via a delivery apparatus such as,for example, a toothbrush. Other methods include contacting the topicaloral gel, mouth spray, toothpaste, dentifrice, tooth gel, tooth powders,tablets, subgingival gel, foam, mouse, chewing gum, lipstick, sponge,floss, petrolatum gel, or denture product or other form with thesubject's teeth and oral mucosa. Depending on the embodiment, the oralcare composition may be used as frequently as toothpaste, or may be usedless often, for example, weekly, or used by a professional in the formof a prophy paste or other intensive treatment.

EXAMPLES

The following examples and descriptions further clarify embodimentswithin the scope of the present invention. These examples are givensolely for the purpose of illustration and are not to be construed aslimitations of the present invention as many variations thereof arepossible without departing from the spirit and scope.

Example A: Examples 1 to 17

Examples 1 to 17 are dentifrice compositions shown below with amounts ofcomponents in wt %. They may be suitably prepared by conventionalmethods chosen by the formulator. Examples 1-8 are inventiveformulations according to the present invention, made with a stannousion source (e.g., stannous chloride) and a single amino acid (e.g.,arginine, citrulline, glutamine or glutamic acid), without present ofzinc ion source respectively. In parallel, comparative formulationsexamples 9-17, are prepared. Examples 9-16 are made with stannous, asingle amino acid, as well as zinc ion source (zinc citrate) at twoconcentrations, while control Example 17 is made without the amino acidor the zinc ion source. All of the compositions are prepared byadmixture of the components in Tables 1 and 2, in the proportionsindicated.

TABLE 1 Inventive Compositions Examples 1 to 8 Amount (Wt %) IngredientsEx. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8 Sorbitol Solution 70%48.000 48.000 48.000 48.000 — — — — (Archer Daniels Midland) SodiumFluoride 0.321 0.321 0.321 0.321 — — — — Arginine 2.00 — — — 2.00 — — —Citrulline — 2.00 — — — 2.00 — — Glutamine — — 2.00 — — — 2.00 —Glutamic Acid — — — 2.00 — — — 2.00 Glycerin — — — — 35.500 35.50035.500 35.500 Propylene Glycol — — — — 7.000 7.000 7.000 7.000 PEG-6 — —— — 7.000 7.000 7.000 7.000 Sodium — — — — 13.000 13.000 13.000 13.000Polyphosphate Trosodium Phosphate — — — — 1.100 1.100 1.100 1.100Dodecahydrate Stannous Fluoride — — — — 0.454 0.454 0.454 0.454 ZincLactate — — — — — — — — Dihydrate Zinc Citrate — — — — — — — — StannousChloride 1.160 1.160 1.160 1.160 0.462 0.462 0.462 0.462 DihydrateSodium Gluconate 1.064 1.064 1.064 1.064 1.099 1.099 1.099 1.099 XanthanGum 0.875 0.875 0.875 0.875 0.250 0.250 0.250 0.250 Carrageenan Mixture1.500 1.500 1.500 1.500 0.600 0.600 0.600 0.600 Iota Silica SilicaAbrasive 16.000 16.000 16.000 16.000 25.000 25.000 25.000 25.000Thickening Silica — — — — 0.750 0.750 0.750 0.750 Sodium Lauryl 7.5007.500 7.500 7.500 7.500 7.500 7.500 7.500 Sulfate (28% soln.) SodiumSaccharin 0.300 0.250 0.300 0.300 0.700 0.700 0.700 0.700 Flavor/sensateoils 1.100 1.100 1.100 1.100 1.200 1.200 1.200 1.200 Sodium Hydroxide0.980 0.980 0.980 0.980 — — — — Water and minors q.s. q.s. q.s. q.s.q.s. qs q.s. q.s. (e.g., color soln.) Total 100% 100% 100% 100% 100%100% 100% 100% Target pH 6.5 6.5 6.5 6.5 6.5 6.5 6.5 6.5

TABLE 2 Comparative Compositions Examples 9 to 17 Amount (Wt %)Ingredients Ex. 9 Ex. 10 Ex. 11 Ex. 12 Ex. 13 Ex. 14 Ex. 15 Ex. 16 Ex.17 Sorbitol 48.000 48.000 48.000 48.000 48.000 48.000 48.000 48.00048.000 Solution 70% (Archer Daniels Midland) Sodium 0.321 0.321 0.3210.321 0.321 0.321 0.321 0.321 0.321 Fluoride Arginine 2.00 — — — 2.00 —— — — Citrulline — 2.00 — — — 2.00 — — — Glutamine — — 2.00 — — — 2.00 —— Glutamic — — — 2.00 — — — 2.00 — Acid Zinc Citrate 0.533 0.533 0.5330.533 1.066 1.066 1.066 1.066 — Stannous 1.160 1.160 1.160 1.160 1.1601.160 1.160 1.160 1.160 Chloride Dihydrate Sodium 1.064 1.064 1.0641.064 1.064 1.064 1.064 1.064 1.064 Gluconate Xanthan 0.875 0.875 0.8750.875 0.875 0.875 0.875 0.875 0.875 Gum Carrageenan 1.500 1.500 1.5001.500 1.500 1.500 1.500 1.500 1.500 Mixture Iota Silica Silica 16.00016.000 16.000 16.000 16.000 16.000 16.000 16.000 16.000 AbrasiveThickening — — — — — — — — — Silica Sodium 7.500 7.500 7.500 7.500 7.5007.500 7.500 7.500 7.500 Lauryl Sulfate (28% soln.) Sodium 0.300 0.2500.300 0.300 0.300 0.250 0.300 0.300 0.300 Saccharin Flavor/ 1.100 1.1001.100 1.100 1.100 1.100 1.100 1.100 1.100 sensate oils Sodium 0.9800.980 0.980 0.980 0.980 0.980 0.980 0.980 0.980 Hydroxide Water and q.s.q.s. q.s. q.s. q.s. q.s. q.s. q.s. q.s. minors (e.g., color soln.) Total100% 100% 100% 100% 100% 100% 100% 100% 100% Target pH 6.5 6.5 6.5 6.56.5 6.5 6.5 6.5 6.5

Example B—Assay for Measuring Improve Endotoxin Neutralization ofAnti-Bacterial Agent in the Biofilms

In order to determine improved endotoxin neutralization ofanti-bacterial agent in the biofilms, the following assay is used toassess LPS binding efficiency of stannous ions via measurement of afluorescent dye that is bound to lipid A of LPS in in situ plaquebiofilms for inventive oral care compositions of the present inventionand controls. Details of the assay are described below.

(a) Substrate for Biofilm Growth

Hydroxyapatite (“HA”) disks are used for in situ growth of biofilms. TheHA disks are designed having three parallel grooves (i.e., 200 μm wide;200 μm deep for two sides' grooves; while 500 μm wide and 500 μm deepfor the middle groove) in each disk. When attaching disks to subject'smouth, keep these grooves vertical, to mimic interproximal gap betweenteeth, which is the hard-to-clean area where plaque generally tends toaccumulate. This model allows the collection of undisturbed plaque fromthe grooves. HA disks are manufactured by Shanghai Bei'erkangbiomedicine limited company.

(b) Wearing the Splint

Human subjects wear the splint. Each subject wears up to 12 HA disks onthe splint to ensure that, at least, 9 HA disks are available after 48hours. A non-limiting example of such a splint and HA disks are shown inFIG. 1 . With reference to FIG. 1 , the device (1) holds a plurality ofHA disks (2 a-2 d). In a specific example, and with reference to FIG. 2, the HA disk (201) has three parallel grooves (203) (the two sides'grooves (203 a and 203 c) are 300 μm wide and 300 μm deep; while themiddle grove (203 b) (in between the two side grooves) is 500 μm wideand 500 μm deep). The middle groove is designed wider and deeper thanthe two sides' grooves so that the HA disk can be more easily separatedinto two identical half-disks for head-to-head comparison purposes. FIG.3 is a schematic of a cross-sectional view of the groove (2003) withbiofilm (2005) therein. Further details of the HA disks are described inUS2017/0056531 (e.g. paragraphs [0019]-[0020]).

Although not shown in FIG. 3 , the disks can be positioned such that therecede is in the inter-dental space between the teeth (since thislocation is prone to plaque (given the difficulty in cleaning, etc.)).The subjects withdraw the splint only during meals (the splint stored inan opaque container in humid conditions) and to perform oral hygieneprocedures Immediately thereafter, the splint is worn again. Subjectsare asked to use a straw when drinking.

(c) In-Situ Biofilms Release from HA Desk

All HA disks are removed from the splint at 48 hours by tweezers.Tweezers are used to hold the edge of HA chips and transfer the HA diskto a 2 mL centrifuge tube containing phosphate buffered saline (PBS)solution. Tweezers are washed thoroughly (water; 75% alcohol; and thendeionized water) before every disk transfer.

(d) Preparation of Toothpaste Supernatant

15 grams of deionized water is added to 5 grams toothpaste (using anyone of the inventive Composition Examples 1-8, Comparative CompositionExamples 9-17. After stirring thoroughly, the mixture is centrifuge at12,000 RPM for 20 minutes. The supernatant is prepared one day beforeusage and stored at 4° C.

(e) Confocal Laser Scanning Microscopy

After the HA disks are removed from the splint. The HA disks are usedfor ex vivo treatment by the different inventive and controlcompositions. After being treated with the subject supernatant andlabeled with microbial fluorescent probe and stannous fluorescent probe(such as described in PCT Publication No. WO2015/139263; Shi et al.),the biofilms in the grooves are measured by confocal laser scanningmicroscopy (“CLSM”) (as described below). Preferably, theneutralized-LPS fluorescent probe is BODIPY-TR-cadaverine (BC)(available from Thermo Fisher). Preferably, the microbial fluorescentprobe is the Molecular Probes™ LIVE/DEAD® BacLight™ system (availablefrom Thermo Fisher).

(f) Disk Preparation

The HA disks are rinsed in PBS solution and each HA disk is divided intotwo halves by tweezers. Thereafter, each half-disk is placed into500-1000 μL of PBS solution statically for 1 minute. Each disk istreated for two minutes by either PBS solution or toothpastesupernatant. Each disk is washed by holding each disk with tweezers,shaken for ten rounds of back and forth in 1 mL of PBS solution, andthen this washing cycle is repeated. Then each disk is immersed into500-1000 μL PBS solution statically for 5 minutes.

(g) Fluorescence Staining and Microscopy

The LPS neutralization effect was evaluated using BODIPY-TR-cadaverine(BC), a fluorescent dye that is bound to lipid A, thereby suppressingits fluorescence. BC is displaced by agents with an affinity for thislipid. When LPS are bound by other ions, e.g., stannous, BC is releasedfrom the LPS and its fluorescence is proportional to the amount of free(unbound) BC present. Therefore, the level of fluorescence indicates theamount of neutralized (bound) LPS versus free (unbound) LPS, and theefficacy of an antibacterial agent in reducing the biofilm's toxicity.The greater the amount of bound LPS, the lower its toxicity.

After treatment and immersing, each half-disk is stained with theBODIPY-TR-cadaverine (BC) probe together with Syto-9 probe (containing 5μM BC probe and 5 μM Sn probe) for 30 minutes in the dark. Afterstaining, each disk is immersed into 500-1000 μL PBS solution staticallyfor 2 minutes. The disks are washed again, by holding each disk withtweezers, shaken for five rounds of back and forth in 1 mL PBS solution,and repeated. For SYTO-9/BC dye stained samples, the followingparameters are used: λex=488 nm/543 nm, λem=500/580 nm, 20× objectivelens, and scanning from bottom of surface bacteria for 60 μm with stepsize=3 μm.

(h) Confocal Laser Scanning Microscopy

The Leica™ TCS SP8 AOBS spectral confocal microscope is used. Theconfocal system consists of a Leica™ DM6000B upright microscope and aLeica™ DMIRE2 inverted microscope. An upright stand is used forapplications involving slide-mounted specimens; whereas the invertedstand, having a 37° C. incubation chamber and CO₂ enrichmentaccessories, provides for live cell applications. The microscopes sharean exchangeable laser scan head and, in addition to their ownelectromotor-driven stages, a galvanometer-driven high precision Z-stagewhich facilitates rapid imaging in the focal (Z) plane. In addition toepifluorescence, the microscopes support a variety of transmitted lightcontrast methods including bright field, polarizing light anddifferential interference contrast, and are equipped with 5×, 20×, 40×,63× (oil and dry) and 100× (oil) Leica™ objective lenses.

The laser scanning and detection system is described. The TCS SP8 AOBSconfocal system is supplied with four lasers (one diode, one argon, andtwo helium neon lasers) thus allowing excitation of a broad range offluorochromes within the UV, visible and far red ranges of theelectromagnetic spectrum. The design of the laser scan head, whichincorporates acousto-optical tunable filters (“AOTF”), anacousto-optical beam splitter (“AOBS”) and four prism spectrophotometerdetectors, permits simultaneous excitation and detection of threefluorochromes. The upright microscope also has a transmission lightdetector making it possible to overlay a transmitted light image upon afluorescence recording.

Leica™ Confocal software is used. The confocal is controlled via astandard Pentium PC equipped with dual monitors and running Leica™Confocal Software. The Leica Confocal Software provides an interface formulti-dimensional image series acquisition, processing and analysis,that includes 3D reconstruction and measurement, physiological recordingand analysis, time-lapse, fluorochrome co-localization, photo-bleachingtechniques such as FRAP and FRET, spectral immixing and multicolourrestoration. Regarding image analysis, the SYTO-9/BC probe stainedsamples are chosen to quantify fluorescence intensity of red and greenpixels. Using the software, the fluorescence intensity ratio (FIR) ofbound LPS/bacterial cell was calculated. This ratio of fluorescenceintensity indicates the relative amount of bound (neutralized) LPS perunit of bacteria, and the efficacy of an agent in reducing the biofilm'stoxicity. The greater the fluorescence intensity ratio, the higher LPSendotoxin neutralization efficacy.

Results: Subjects are treated with the Inventive Composition Ex. 1-4(i.e., Sn+2.00% Amino Acid without Zinc), Comparative Composition Ex.9-16 (i.e., Sn+2.00% Amino Acid with Zinc), Comparative Composition Ex.17 (i.e., Sn without amino acid nor Zinc), and the PBS as negativecontrol. The results are provided in Table 3.

TABLE 3 Endotoxin neutralization in Biofilm Fluorescence intensity ratio(FIR) of bound LPS/bacterial cell Inventive Composition Ex. 1 0.73Inventive Composition Ex. 2 0.79 Inventive Composition Ex. 3 0.8Inventive Composition Ex. 4 0.83 Comparative Composition Ex. 9 0.64Comparative Composition Ex. 10 0.66 Comparative Composition Ex. 11 0.68Comparative Composition Ex. 12 0.69 Comparative Composition Ex. 13 0.6Comparative Composition Ex. 14 0.64 Comparative Composition Ex. 15 0.64Comparative Composition Ex. 16 0.65 Comparative Composition Ex. 17 0.63Control (PBS) 0

The results demonstrate the markedly higher Fluorescence intensity ratio(FIR) of bound LPS/bacterial cell with the Inventive Composition Ex. 1(0.73), Inventive Composition Ex. 2 (0.79), Inventive Composition Ex. 3(0.8), Inventive Composition Ex. 4 (0.83) over the ComparativeComposition Ex. 9-17 (0.6-0.69) and the Control PBS (0). In effect thisdata supports the improved endotoxin neutralization of the stannous ionin the biofilms when combined with an amino acid (e.g., arginine,citrulline, glutamine and glutamic acid) and free of Zn over the controlwith an amino acid (e.g., arginine, citrulline, glutamine and glutamicacid) and Zn salts. Further comparing Inventive Composition Ex. 1 to 4with Comparative Composition Ex. 17, the data show improved endotoxinneutralization of the stannous ion in the biofilms when combined with anamino acid vs. only stannous ion without amino acid (0.73-0.83 vs.0.63).

Example C—Assay for Measuring Improved Wound Healing of Human GingivalFibroblasts

In-vitro human gingival fibroblasts are used to assess the effects ofwound healing migration as a result of treatment with InventiveCompositions and Comparative Compositions. The method involves threestages:

Stage 1—Culturing Primary Human Gingival Fibroblasts (“HGF”)

Human gingival fibroblasts are collected from tooth extraction patientsand washed with 5 mL of PBS (phosphate buffered saline). The tissues arechopped into small pieces and placed into 15 mL centrifuge tube. Thesamples are digested with equal amounts of 1 mL 8% dispase and 1 mL 6%collagenase for 1 hr at 37° C., during which time the samples need to beshaken every 15 minutes. Once the digestion process is complete, thetube is centrifuged at 1100 RPM for 6 minutes at room temperature. Aftercentrifugation, a pellet of cells is formed in the bottom of the tubeseparating them from the supernatant solution. Then the supernatant isdiscarded and the cell pellet is suspended in 3 mL of fresh MinimumEssential Medium (“MEM”, available from Thermo Fisher) culture mediathen transferred to a petri dish. The petri dish with cells are placedin the incubator at 37° C. with 5% CO₂ for about 10 days. The petri dishis checked for changes in media color every two days. Fresh culturemedia is replaced if changes in media color occurred.

Stage 2—Sub-Culturing Human Gingival Fibroblast

When there is 80-90% cell monolayer coverage of the petri dish, then thepresent culture media is removed and washed with 5 mL of PBS. 1 mL 0.25%trypsin-EDTA solution is added and the cells sit for about 1-2 minutesat 37° C. until the cells are visibly round-shaped. It may be necessaryto tap the petri dish to remove any sticky cells from the petri dishsurface. At least 1 mL of fresh MEM culture media is added to inactivatethe trypsin and the cells are collected into a 15 mL centrifuge tube.The tube is then centrifuged at 1100 RPM for 6 minutes at roomtemperature. The supernatant is discarded and cell pellet isre-suspended in 4 mL of fresh MEM culture media in the same centrifugetube. 4 petri dishes are each placed with 1 mL cell suspension and 9 mLfresh MEM culture media in the incubator at 37° C. with 5% CO₂ for about3-5 days until 80-90% cell monolayer coverage on the petri dishes areobserved. This stage should be repeated 2-4 times before the woundhealing assay to achieve the highest cell viability.

Stage 3—Wound Healing Assay

When there is 80-90% cell monolayer coverage on the petri dishes, thepresent culture media is removed and washed with 5 mL of PBS. 1 mL 0.25%trypsin-EDTA solution is added and the cells sit for about 1-2 minute at37° C. until the cells are visibly round-shaped. It may be necessary totap the culture petri dish to remove any sticky cells from the petridish surface. At least 1 mL of fresh MEM culture media is added toinactivate the trypsin and the cells are collected into a 15 mLcentrifuge tube. The tube is then centrifuged at 1100 RPM for 6 minutesat room temperature. The supernatant is discarded and cell pellet isre-suspended in 6 mL of fresh MEM culture media. 1 mL cell suspensionand 1 mL fresh MEM culture media are respectively added into each wellof a 6-well plate. The plates are incubated at 37° C. with 5% CO₂ until50-70% cell monolayer coverage is formed. The outer bottoms of wells arethen marked with a line in middle as the reference line during imageacquisition. A wound is created manually by scraping the right half ofcell monolayer with a sterilized 1 mL pipette tip. The cells are washedwith 2 mL PBS to remove any suspended cells until no suspended cells arevisible. 2 mL culture media, and 2 ml culture media containing 1%Comparative Compositions or 2 mL culture media containing 1% InventiveCompositions are added to the wells.

High density digital images of the HGF are captured with an Olympus®IX71 digital SLR camera with an Olympus® UIS2 WHN10X objective lens. Thefirst images are acquired at time 0 hr (i.e., Baseline) by using themiddle line markings on the plates as a reference line. The plates arethen incubated at 37° C. with 5% CO₂ for varying time intervals asdescribed below. The matched photographed region is acquired aspreviously, and images are acquired at later time intervals (e.g., 24hrs, 48 hr, 72 hrs, etc.) after baseline to assess the cell coverage (%)as an indication of the wound healing performance under the differenttreatment legs Images are evaluated by Wimasis® WimScratch software(available from Wimasis GmbH, Germany) to determine the degree (i.e.,percentage) of HGF cell coverage (i.e., wound healing) pass the markedwound boundary, as compared to the matching baseline image for eachsample. WimScratch software utilizes advanced edge detection and overlaytechniques to recognize cells and blank area, i.e. the green overlay inthe image represents the cell-covered area of the particular image andthe grey area represents the wound area. The readout is presented forboth area and is normalized as percent of total area.

Results: With reference to Table 4, the results show that the InventiveComposition Ex. 1 containing Arginine and Ex. 2 containing Citrullineeffectively improve the wound healing though increased cell coverage(i.e. 8.70%=58.70% total coverage—50.00% baseline) post the marked woundrelative to the lower cell coverage (6.40%=56.40% total coverage—50.00%baseline) for the HGF treated with the Comparative Composition Ex. 17without amino acid and Zinc.

TABLE 4 Wound Healing Increase 24 hrs, 48 hrs, 72 hrs Post-Treatment 24h 72 h Inventive Composition Ex. 1  8.70% 28.30% Inventive CompositionEx. 2 16.70% 37.80% Comparative Composition Ex. 17  6.40% 22.80%

Example D—Mouth Rinse Compositions

Mouth rinse compositions according to the present invention are shownbelow as Examples 18-20 in Table 5. These compositions contain astannous ion source and an amino acid without presence of zinc.Preferably, these compositions exhibit improve Gum Health benefitsversus commercially available formulations without these ingredients.

TABLE 5 Mouth Rinse Formulations Amount (Wt %) Ingredients Ex. 18 Ex. 19Ex. 20 Glycerin 5.000 5.000 5.000 Stannous Chloride Dihydrate 0.1160.116 0.116 Arginine 0.050 0.500 2.00 Sucralose 0.030 0.030 0.030Ethanol 5.000 5.000 5.000 Methyl Paraben 0.020 0.020 0.020 PropylParaben 0.005 0.005 0.005 Flavor/sensate oils 0.100 0.100 0.100Performathox 490 0.050 0.050 0.050 Water q.s. q.s. q.s. Total 100% 100%100% Target pH 6 6 6

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

Every document cited herein, including any cross referenced or relatedpatent or application and any patent application or patent to which thisapplication claims priority or benefit thereof, is hereby incorporatedherein by reference in its entirety unless expressly excluded orotherwise limited. The citation of any document is not an admission thatit is prior art with respect to any invention disclosed or claimedherein or that it alone, or in any combination with any other referenceor references, teaches, suggests or discloses any such invention.Further, to the extent that any meaning or definition of a term in thisdocument conflicts with any meaning or definition of the same term in adocument incorporated by reference, the meaning or definition assignedto that term in this document shall govern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A dentifrice composition comprising: (a) stannousfluoride; (b) stannous chloride; and (c) arginine, wherein thedentifrice composition is substantially free of a zinc ion source and apolyphosphate.
 2. The dentifrice composition of claim 1, wherein thecomposition comprises from 0.01% to 5%, by weight of the composition, ofa thickening agent selected from a thickening polymer, a thickeningsilica, or a combination thereof.
 3. The dentifrice composition of claim1, wherein the composition comprises from 1% to 60%, by weight of thecomposition, of a humectant.
 4. The dentifrice composition of claim 3,wherein the humectant comprises glycerin, sorbitol, or combinationsthereof.
 5. The dentifrice composition of claim 1, wherein thecomposition has a pH of 9.0 or less.
 6. The dentifrice composition ofclaim 1, wherein the composition comprises abrasive.
 7. The dentifricecomposition of claim 6, wherein the abrasive comprises silica abrasive,calcium-containing abrasive or combinations thereof.
 8. The dentifricecomposition of claim 7, wherein the silica abrasive comprisesprecipitated silica.
 9. The dentifrice composition of claim 7, whereinthe calcium-containing abrasive comprises calcium carbonate, dicalciumphosphate, tricalcium phosphate, calcium orthophosphate, calciummetaphosphate, calcium polyphosphate, calcium oxyapatite, sodiumcarbonate, sodium bicarbonate, or combinations thereof.
 10. A dentifricecomposition comprising: (a) stannous fluoride; (b) arginine; and (c)abrasive, the abrasive comprising precipitated silica,calcium-containing abrasive, or combinations thereof wherein thedentifrice composition is substantially free of a zinc ion source and apolyphosphate.
 11. The dentifrice composition of claim 10, wherein thedentifrice composition comprises stannous chloride.
 12. The dentifricecomposition of claim 10, wherein the composition comprises from 0.01% to5%, by weight of the composition, of a thickening agent selected from athickening polymer, a thickening silica, or a combination thereof. 13.The dentifrice composition of claim 10, wherein the compositioncomprises from 1% to 60%, by weight of the composition, of a humectant.14. The dentifrice composition of claim 13, wherein the humectantcomprises glycerin, sorbitol, or combinations thereof.
 15. Thedentifrice composition of claim 10, wherein the composition has a pH of9.0 or less.
 16. The dentifrice composition of claim 10, wherein thecalcium-containing abrasive comprises calcium carbonate, dicalciumphosphate, tricalcium phosphate, calcium orthophosphate, calciummetaphosphate, calcium polyphosphate, calcium oxyapatite, sodiumcarbonate, sodium bicarbonate, or combinations thereof.